Automated lumber cutting and delivery system

This application is a continuation of U.S. application Ser. No. 16/757,063, a National Stage Entry application, which claims priority to, PCT Patent Application No. PCT/US2018/056723, filed Oct. 19, 2018, which claims priority to U.S. Provisional Patent Application No. 62/575,335, filed Oct. 20, 2017, all of which are hereby incorporated by reference in their entireties.

The present invention generally relates to automated lumber cutting and delivery systems. More particularly the invention relates to the processing and delivery of sections of lumber to a desired location.

Rising labor costs and demands for more time and cost-efficient construction have made it desirable to construct building components and modules off site at specialized fabrication facilities. With wood frame structures, especially prefabricated residential structures, there are great economies to be realized by providing automated equipment that can measure and cut lumber components utilized in wall panels, roof trusses, and other prefabricated items. Where significant quantity of a particular structural element, such as roof trusses, is needed, the use of such automated systems can greatly decrease construction time and lower costs, especially labor costs. The economies of this approach are very appealing for custom structural designs. For wood structures where the framing is constructed on site, precutting and marking lumber off site location can create a kit design minimizing measuring, sawing, and the need for specialized labor on site. This can result in faster construction as well as minimized cost. On-site construction errors can also be minimized.

Prefabricated roof trusses in particular, generally include multiple pieces of lumber that must be precision cut to specific lengths as well as having precision mitered ends to form tight-fitting joints. A typical roof truss includes two top chords, a bottom chord, several webs and many also include wedges and overhangs. Many of these pieces require a preparation of mitered cuts at the ends of the lumber pieces. Truss plates with teeth are typically utilized to securely make the connection. For a truss to achieve its maximum structural integrity and strength, the joints between the various wooden parts should be tight fitting. Thus precision cutting of truss members is quite important to creating a truss that meets engineering standards.

In one aspect, a lumber cutting and delivery system for use in assembling trusses on a truss table comprises a saw configured to receive a piece of material therein. The saw is configured to cut the piece of material into one or more pieces and cut the piece of material at different lengths and angles so that at least some of the one or more pieces are the components of at least one truss. A trunk conveyor system is positioned to receive the one or more pieces cut from the saw. The trunk conveyor system has a first conveying element to transport the one or more pieces over a distance in a travel direction and an ejector configured to discharge the one or more pieces from the first conveying element in a first discharge direction. A branch conveyor system is configured to receive the one or more pieces discharged from the trunk conveyor system in the first discharge direction. The branch conveyor system has a main conveying element to transport the one or more pieces.

In another aspect, a lumber cutting and delivery system for use in assembling wooden constructs on a table comprises a saw configured to receive a piece of material therein. The saw is configured to cut the piece of material into a component member to be used in the creation of the wooden construct, a waste member to be discarded, and/or a remainder member capable of being cut by the saw again into an additional component member. A trunk conveyor system is positioned to receive the component member, waste member, and/or remainder member cut by the saw. The trunk conveyor system has a first conveying element to transport the component member, waste member, and/or remainder member over a distance and an ejector configured to selectively discharge the component member, waste member, and/or remainder member from the first conveying element. A first receiving unit is disposed adjacent to the first conveying element and is configured to receive the component member, waste member, and/or remainder member discharged from the first conveying element by the ejector.

Corresponding parts are indicated by corresponding reference characters throughout the several views of the drawings.

Referring to, an automated lumber cutting and delivery system or truss assembly line constructed according to the principles of the present invention is generally indicated at. The lumber cutting and delivery systemincludes a loading system, generally indicated at, that is capable of picking lumber and placing it on an infeed conveyor, generally indicated at. Lumber or another material capable of being cut into pieces for use in forming a construct can be used. Although an automated loading systemis desirable, a semi-automated or entirely manual loading system could be used. The infeed conveyorleads to a cutting system (e.g., saw), generally indicated at, that cuts the lumber according to predetermined instructions and discharges the pieces of cut lumber to a transition conveyor, generally indicated atthat feed the cut lumber components to a trunk conveyor system, generally indicated at. A branch conveyor system, generally indicated at, is located to one side of the trunk conveyorand leads to a truss table, generally indicated at. As described more fully below, the lumber cutting and delivery systemcan also include one or more of a remote station, generally indicated at(), a stacker (not shown), a ramp assembly, generally indicated at(), a robotic cell, generally indicated at(), a waste collection system, generally indicated at(), a culling station (not shown), and an automated guided cart (not shown) as well as additional truss tables, loading systems, infeed conveyors, cutting systems, transition conveyors, trunk conveyor systemsand branch conveyor systems(see). As explained in more detail below, the lumber cutting and delivery systemcan contain any number of these components. The lumber cutting and delivery systemalso includes a control system, generally indicated at(), which controls the operation of the lumber cutting and delivery system (e.g., the operation of each component thereof).

The lumber cutting and delivery systemof the present invention is modular such that the components making up the system can be combined in varying arrangements as desired, as described in more detail below. Although the automated lumber and delivery systemis described herein in terms of constructing trusses, the system has application to the production of other items. For example, and without limitation, the system could be used in the manufacture of walls and floor trusses. Accordingly, the lumber cutting and delivery systemcan be configured to deliver cut pieces of lumber L to other pieces of manufacturing equipment, such as wall and floor truss manufacturing equipment, instead of or in combination with a truss table. In general, the lumber cutting and delivery systemmay be used to deliver cut pieces of lumber to a location to create any lumber construct, particularly (but not exclusively) those which are joined together using nailing plates.

Referring to, the loading systemgenerally includes a pick up armmovably connected to a gantryand a storage area. The storage areaincludes at least one bunklocated beneath the gantryand configured to hold one or more sizes of lumber L in a stacked arrangement. Preferably, a plurality of bunksare located beneath the gantry, each able to store one or more sizes of lumber L in a stacked configuration. This way, the lumber cutting and delivery systemcan access a variety of different lumber L sizes that may be needed to create trusses of varying sizes and construction with the most efficient use of lumber. The bunkscan be movable to allow for easier loading of lumber L. For example, the bunkis supported by wheels and configured to slide along a tracksuch that when the bunk is empty, the bunk can be moved from underneath the gantry, loaded with lumber L and then moved back underneath the gantry. By following the track, the bunkcan be placed in the same position underneath the gantryafter the bunk has been loaded with lumber L. In one embodiment, the loading systemincludes additional bunkslocated outside the gantryand in-line with the bunks beneath the gantry (). The bunkslocated outside the gantrycan be pre-loaded with lumber L so that once a bunk located beneath the gantry is empty, the empty bunk can be quickly replaced by the pre-loaded bunk. In addition, these additional bunksmay be movable between lines such that the additional bunks can be moved in-line with any of the bunks located beneath the gantry (see). In this manner, the lumber cutting and delivery systemcan stage a large amount of lumber L to feed the system and an operator can quickly and easily load the staged lumber into the loading systemonce a bunkis empty. In one embodiment, each bunkmay be coupled to an automated guide cart (not shown), described below, which can automatically remove the empty bunk and move the pre-loaded bunk into position. In another embodiment, each bunk may itself be configured as an automated guide cart. “Boards”, “lumber”, “lumber members” and “pieces of lumber” are intended to be interchangeable herein unless the context clearly indicates the contrary.

The loading systemis configured to transport the pieces of lumber L from the storage areato the infeed conveyor. The pickup armis movable along the length of the gantryand can extend below the gantry to reach the lumber L stored in the bunks. The pickup armuses suction to pick up a piece of lumber L from the bunk. Once the pickup armgrabs a piece of lumber L, the pickup arm moves along the length of the gantryand places the lumber on the infeed conveyor. The loading systemcan also include sensors capable of detecting the amount of lumber L contained in the bunkand convey that information to a control system. When the amount of lumber L in the bunkis low, the sensors convey that information to the control system. The control systemcan then send a signal to an operator indicating the need to load more lumber L onto the bunkor replace the empty bunk with a pre-loaded bunk (manually or automatically). The control systemcan also contain an inventory of the lumber L contained in the bunkand display the inventory to the operator. An example of a suitable loading systemis the Ranger RS™ lumber retrieval system available from Acer Inc.

In one embodiment, the lumber cutting and delivery systemmay include a culling station (not shown) before the loading system. The culling station is configured to analyze pieces of lumber L received in a lumber shipment before the pieces of lumber are moved into the bunks. The culling station is configured to sort the pieces of lumber L into usable (e.g., good) pieces of lumber and unusable (e.g., bad) pieces of lumber. In practice, generally, up to 25% of the lumber L received in a lumber shipment may be unusable. Usable pieces of lumber L can be used to construct a wooden truss or other constructs and can be fed into the subsequent components of the lumber cutting and delivery system. Unusable pieces of lumber L contain one or more defects which prevent the piece of lumber from being suitable to build a wooden truss and/or fed into the subsequent components of the lumber cutting and delivery system. For example, pieces of lumber L may be defective and unusable because the piece of lumber is chamfered, twisted, bowed, missing chunks, cracked, severely knotted, etc. The culling station includes sensors, such as cameras, that scan each piece of lumber L as the lumber is fed into the culling station. In one embodiment, the culling station may be configured to automatically remove pieces of lumber L from a lumber shipment (e.g., debunk the lumber) and feed the lumber into the culling station. In other embodiments, this may be done manually by an operator. The culling station and/or the control systemanalyzes the data from the sensors and determines if the scanned piece of lumber L is usable or unusable. If the piece of lumber L is usable, the culling station can direct the usable piece of lumber to a usable lumber pile. If the piece of lumber L is unusable, the culling station can direct the unusable piece of lumber to an unusable lumber pile. The usable piece of lumber L can then be transferred to the bunksof the loading system. This can be done manually by an operator or automatically using the automated guided carts described herein. The culling station can position and/or arrange the usable and unusable pieces of lumber L so that they are easily transportable, for example by stacking the pieces of lumber on a cart (automated or manual) or a pallet. The culling station can be connected to the control systemand may send and receive signals (e.g., instructions, operational data, etc.) to and from control system.

Referring to, the infeed conveyorreceives the lumber L from the loading systemand transports the lumber L to the cutting systemfor cutting. The infeed conveyorhas a transverse conveyor portionand a longitudinal conveyor portion. The transverse conveyor portionreceives the lumber L from the pickup arm of the loading systemand transports the lumber in a direction that is transverse to the lumber's longitudinal axis to the longitudinal conveyor portion. The longitudinal conveyor portionis aligned with the cutting systemand transports the lumber L in a longitudinal direction parallel to the lumber's longitudinal axis, to the cutting system. Further details of infeed conveyorsmay be found in U.S. Pat. No. 7,011,006, incorporated herein by reference. The infeed conveyormay also contain an orienter which orients each piece of lumber L in a desired configuration. For example, lumber L is often bowed or curved over its length. The orienter positions each piece of lumber L received on the infeed conveyorsuch that the bow is always facing the same direction. In other embodiments, the lumber cutting and delivery systemmay not include a loading system. In this embodiment, the pieces of lumber L may be manually loaded onto the transverse conveyor portion of the infeed conveyorby an operator or a robotic cell, as discussed below, may be used to load the pieces of lumber. The infeed conveyormay also include a sensor configured to detect the width of the piece of lumber L in order to confirm the piece of lumber being delivered to the cutting systemis the correct width.

Referring to, the cutting systemreceives the lumber L from the infeed conveyorand cuts the piece of lumber to form the desired truss member. For example, the cutting systemmay receive data from a production software of the control system, described in more detail below. The data can be used by the cutting systemto cut the pieces (e.g., truss members) used to construct a particular truss or other construct. As shown in, the cutting systemincludes a human-machine interfacewhich can be mounted on the cutting system and allows the operator or production manager to interface with the cutting system, as described in more detail below. The cutting systemcuts the lumber L to the desired length with the desired angled miter cuts on each end to form the truss member. The cutting systemgenerally includes a multi-position saw capable of cutting a piece of lumber L at any angle, a gripping assembly capable of securing the lumber when it is being cut, and a discharge system capable of moving the lumber out of the cutting system. The cutting systemmay also include a printer that can mark the lumber L on one or more sides. The printer can mark the lumber L with identification information so that the operator and/or subsequent components of the lumber cutting and delivery systemcan identify the cut piece of lumber. The printer can also mark the lumber L to show connector (e.g., nailing) plate locations. Once the lumber L is cut by the cutting systemin the desired configuration to form the truss member, the truss member is then transported out of the cutting system by the discharge system. In the illustrated embodiments (), the cutting systemmoves the cut pieces of lumber L (e.g., truss members) onto a transition conveyor. One example of a suitable cutting systemis the MatchPoint BLADE™ wood processing system from MiTek Industries, Inc.

When cutting truss members from the lumber L, the truss members are generally a different length than that of the lumber. Thus, the cutting of the truss member from the lumber L results in a leftover segment of lumber. This leftover segment of lumber L is also transported out of the cutting systemby the discharge system. The leftover segment of lumber is classified as either waste or remainder. The leftover segment is waste if it is too short to be used to form a truss member. Waste is generally discarded by the operator. The leftover segment is remainder if it is long enough to be cut again to form a truss member. Remainder is generally collected and fed back into the lumber cutting and delivery systemby the operator to be cut into a truss member for use in a truss. The operator and/or the control systemmakes the waste/remainder determination for the leftover segment. “Truss member”, “waste” and “remainder” are all a subset of “lumber” and are intended to be interchangeable with “lumber” or a similar term as described above unless the context clearly indicates the contrary.

Referring to, the transition conveyortransports the lumber L, which can be classified as a truss member, waste or remainder, to the trunk conveyor system. The transition conveyorincludes a transition conveyor belt(broadly, “conveying element”) positioned next to the cutting system. The transition conveyor beltreceives the lumber L from the discharge system and transports the lumber to the trunk conveyor system. The transition conveyorincludes a motor(e.g., electric motor) operative coupled to the transition conveyor beltand configured to drive movement of the transition conveyor belt. As explained in more detail below, the transition conveyor beltis connected to and controlled by the control system.

Referring to, the trunk conveyor systemhas a front endpositioned to receive the lumber L from the transition conveyorand a rear end. It will be understood that the trunk conveyor systemcould receive lumber L directly from the cutting system(or other component), or additional equipment (not shown) may be interposed between the branch conveyor systemand the cutting system within the scope of the present invention. The trunk conveyor systemincludes a first conveyor belt(broadly, “conveying element”) spanning between the front and rear ends,and positioned to receive the lumber L and transport the lumber over a desired distance. The trunk conveyor systemalso includes an ejector, capable of pushing the piece of lumber L off of either side of the first conveyor belt. In the illustrated embodiment, the ejectoris a movable swing arm positioned above the first conveyor belt. It is to be understood that other ejectors than described herein, such as conveyor having diverter system using multiple rollers, are within the scope of the present invention. For example, the ejector could be a series of rollers that swing at the desired angle to direct the pieces of lumber L off either side of the first conveyor belt or a linearly movable push bar that pushes the pieces of lumber L off either side. The trunk conveyor systemincludes a motor(e.g., electric motor) operative coupled to the first conveyor beltand configured to drive movement of the first conveyor belt.

The swing armincludes an elongated pusher barand at least one rotating member. The elongated pusher baris in a parallel configuration with the first conveyor beltand positioned just above the first conveyor belt such that the bar can come into contact with the lumber L resting on the first conveyor belt. Each rotating memberhas a first end portion and a second end portion. The first end portion of each rotating member is pivotally connected to the pusher barwith a connector bracketand a pin. The connector bracketis secured to the top of the pusher bar. The pinis secured to and extends from the connector bracketinto a hole in the first end portion of the rotating member(). The pinis coupled to the first end portion of the rotating membersuch that the pin is free to rotate in the hole while the rotating member supports the weight of the pusher bar(or a portion thereof if there are multiple rotating members). The second end portion of each rotating memberis secured to a shaftfor conjoint movement with the shaft. The shaftis rotatably connected to a frameof the trunk conveyor systempositioned above the first conveyor belt. More specifically, the shaftis connected to the frameat a location generally above the center line in the longitudinal direction of the first conveyor belt. Preferably, at least two rotating membersconnect the barto the frame.

The shaftof one of the rotating members, the middle rotating member in the illustrated embodiment, is connected to a rotation bracket(). The rotation bracketincludes a first portion, a second portionextending from the first portion in a direction that is transverse to the first portion and a third portionextending from the second portion in a direction that is generally parallel to the first portion. The rotation bracketdefines an openingconfigured to receive a shaft and connect the rotation bracket to the shaft at the intersection of the first and second portions,such that rotation of the rotation bracketrotates the shaft. A connector tabextends from an intermediate part of the first portionin a direction that is transverse to the first portion and generally opposite the direction in which the second portion extends. The connector tabis pivotably connected to an end of a pistonof a linear actuatorcapable of extending and retracting the piston a set distance in a linear direction. The linear actuatoris mounted on the frameof the trunk conveyor system() to pivot with respect to the frame. As the linear actuatorextends the piston, the rotation bracketis rotated about the shaft, turning the shaft and moving the barof the swing armtoward the second side of the first conveyor belt. As the linear actuatorretracts the piston, the rotation bracketis rotated in the opposite direction, turning the shaftthe opposite direction and moving the pusher barof the swing armtoward the first side of the first conveyor belt. As the swing armsweeps across the first conveyor beltfrom one side toward the other, any lumber L located on the first conveyor belt is pushed off either the first or second side of the first conveyor belt. Thus, the swing armcan push the lumber L off the first side of the first conveyor beltin a first direction that is transverse to the first conveyor belt. Likewise, the swing armcan push the lumber L off the second side of the first conveyor beltin a second direction that is transverse to the first conveyor belt and opposite the first direction.

Referring particularly to, the shaftsnot connected to the rotation bracketare each pivotably mounted on a respective cross memberof the frameand are each secured to an end of an L-shaped bracketfor conjoint rotation with the L-shaped bracket. An opposite end of the L-shaped bracketis pivotably connected to a shaft bar. Each shaft barspans between the L-shaped bracketand the rotation bracketand is pivotably connected to the L-shaped bracket and a third portionof the rotation bracket. The shaft barcan span between two L-shaped brackets, an L-shaped bracket and a rotation bracketor any combination of L-shaped brackets and rotation brackets. There can be multiple shaft barseach spanning between adjacent L-shaped and rotation brackets,or a single bar spanning between and across all the L-shaped and rotation brackets, or any combination thereof. For example, in the illustrated embodiment, there are three shaftscorresponding to three rotating memberspositioned along the frame. The middle shaftis connected to the rotation bracketand the two end shafts are connected to L-shaped brackets. The first shaft barspans between the L-shaped bracketof one end shaftto the rotation bracketand the second shaft bar spans between the L-shaped bracket of the other end shaft to the rotation bracket. This links all the shaftstogether such that the rotation of the rotation bracketby the pistonconjointly rotates the L-shaped bracketsof the shafts located on each end. Accordingly, the shaft barsoperatively connect the end shaftsto the rotation bracketand the linear actuator. Thus, with this linking arrangement, the rotation bracketcan impart a force on every shaftin unison to move the barof the swing armfrom one side to the other side of the first conveyor belt.

Stopscan also be positioned on the frameto engage the rotation bracketat set positions to stop the rotation of the rotation bracket (). The stopsprevent the rotation bracketfrom over rotation. The stopsare set to engage the rotation bracketsuch that the barof the swing armis positioned on a respective one of the first and second sides of the first conveyor beltwhen the rotation bracket engages one of the stops. More specifically, a free end of the first portionopposite the openinghas a side engagement surfaceconfigured to engage the stop to prevent over rotation when the linear actuator retracts the piston. Likewise, a free end of the second portionopposite the openinghas a side engagement surfaceconfigured to engage another stopto prevent over rotation when the linear actuatorextends the piston. In one embodiment, the trunk conveyor systemincludes a cover (not shown) connected to the frameand covering the shaft bars, L-shaped brackets, rotation bracket, stopsand linear actuator.

In one embodiment of the trunk conveyor system(not shown), the rotation bracketimparts a force only on a single shaftto move the swing arm. In this embodiment, the rotation bracket is connected only to the single shaftof a rotation memberand the linear actuator. No shaft barsare used to connect the shaftsof additional rotation memberswith the rotation bracket. In this embodiment, a rotation bracket may not include the third portionof the rotation bracket. In this embodiment, when rotated by the linear actuator, as described above, the rotation bracket rotates the shaftto move the barof the swing armfrom one side of the first conveyor beltto the other as described above. In this arrangement, any additional rotating membersprovide support for the bar. In this embodiment, it is appreciated that only one shafthas force applied to rotate and move the swing arm. The shaftsof any additional rotating membersrotate as a response to the rotation of the swing armand do not apply any force to rotate the swing arm. In either configuration, the rotation bracket rotates about 90 degrees.

The trunk conveyor systemincludes a sensing systempositioned toward the front end. In the illustrated embodiment, the sensing systemcomprises two light bar sensorsplaced on directly across from each other on opposite sides of the first conveyor beltalthough other sensors are within the scope of the present invention. The sensorsare positioned above the first conveyor beltsuch that as a piece of lumber L is transported by the first conveyor belt, the sensors are able to tell when the piece of lumber is between them. In this manner, the sensorscan tell when the leading and trailing edges of the piece of lumber L have passed through the sensors. The sensorsthen send a signal to the control system indicating the lumber L is on the first conveyor belt. As described in more detail below, the control systemthen directs the lumber L to where it needs to go. The control systemis connected to the trunk conveyor systemand can tell the trunk conveyor system to operate the swing armto push the lumber L onto a receiving unit on either side of the first conveyor beltor decide not to operate the swing arm and transport the lumber to the end of the first conveyor belt.

Thus, the trunk conveyor systemis able to transport the lumber L to three different locations, the first or second side of the first conveyor beltor the rear end of the first conveyor belt. At each of these locations, a receiving unit can be placed to receive the lumber L from the trunk conveyor system. An arrangement where less than or greater than three receiving units are positioned adjacent to the trunk conveyor systemis also contemplated. In the preferred embodiment, at least one receiving unit is positioned next to the trunk conveyor systemto receive the lumber L therefrom. As discussed in more detail below, each receiving unit can be, but not limited to, another trunk conveyor system, another transition conveyor, a branch conveyor system, a stacker (not shown), a ramp assemblyand/or a waste collection system. These system components are exemplary only. Other components could be used as receiving units without departing from the scope of the present invention. The ability of the trunk conveyor systemto transport the lumber L to three different receiving units, especially to either side of the first conveyor belt, is important in some embodiments to the modularity of the lumber cutting and delivery systemas discussed in more detail below.

Referring to, another embodiment of a trunk conveyor system is generally indicated at′. Trunk conveyor system′ is analogous to trunk conveyor systemand, thus, corresponding parts have the same reference numeral with a trialing prime (′). Trunk conveyor system′ is shorter than trunk conveyor system. Accordingly, trunk conveyor system′ only has two shafts′ connecting the push bar′ of the ejector′ to the frame′. Likewise, the trunk conveyor system′ only includes a single shaft bar′ extending between and connecting the rotation bracket′ and the L-shaped bracket′. Trunk conveyor system′ operates in the same way as trunk conveyor system.

Referring to, the branch conveyor systemis one receiving unit which may be positioned to receive pieces of lumber L from the trunk conveyor system. The branch conveyor systemhas a front endpositioned adjacent to one side of the first conveyor beltand a back endspaced apart from the front end with a main conveyor belt(broadly, “main conveying element”) spanning between the front and back ends. The branch conveyor systemreceives the lumber L from the trunk conveyor systemwhen the ejectorof the trunk conveyor system pushes the lumber onto the main conveyor beltat the front endof the branch conveyor system. At least one guide (not shown) extends between the side of the trunk conveyor systemand the front end of the branch conveyor systemand supports the lumber L as the lumber slides onto the branch conveyor system. In one embodiment, there are a plurality of guides longitudinally spaced apart along the side of the trunk conveyor system, each guide being a piece of sheet metal with an upper edge extending downward from the side of the trunk conveyor system to the front endof the branch conveyor system(e.g., the front end of the branch conveyor system is positioned below the first conveyor belt). In one embodiment, one of the guides of the plurality of guides is an angled surface extending between the two components. The branch conveyor systemtransports the lumber L in a direction that is generally transverse to the lumber's longitudinal axis and the trunk conveyor system.

The branch conveyor systemmay also include additional secondary conveyorsspaced apart from each other and the main conveyor belt. The additional secondary conveyorsare parallel to the main conveyor beltand span from the front to back end,of the branch conveyor system. A drive trainoperatively connects the secondary conveyorstogether and to the main conveyor beltto move the secondary conveyors and main conveyor belt together and at the same speed. The branch conveyor systemincludes a motor(e.g., electric motor) operative coupled to the drive trainand configured to drive movement of the main conveyor beltand secondary conveying elements. The main conveyor beltis wide enough to support smaller lengths of lumber L. Preferably the main conveyor beltis at least 3 feet wide. The secondary conveying elementsare spaced apart from the main conveyor beltand are used, along with the main conveyor belt, to support lumber L of longer lengths. Accordingly, the main conveyor beltsupports pieces of lumber L of shorter lengths and the main conveyor belt in combination with one or more the secondary conveying elementssupports pieces of lumber of longer lengths. In the illustrated embodiment, each secondary conveying elementcomprises a continuous chain. In other embodiments, one or more of the secondary conveying elementsmay be a wide conveyor belt like the main conveyor belt. The secondary conveyorsare positioned to lie in the same generally horizontal plane of the main conveyor belt.

The branch conveyor systemmay also include at least one branch conveyor system sensorpositioned adjacent to and facing the main conveyor belt. The branch conveyor system sensoris positioned above the main conveyor beltand able to sense when a piece of lumber L is in front of it. Thus, similar to the sensorsof the trunk conveyor system, the branch conveyor system sensorscan tell when a leading and trailing edge of the piece of lumber L has passed through the sensors. The branch conveyor system sensorsthen send a signal to the control system indicating a piece of lumber L is in front of the sensor and on the main conveyor belt. The control system can then tell the branch conveyor systemto continue operating the main conveyor beltand secondary conveying elementsor stop them. In the preferred embodiment, four branch conveyor system sensorsare positioned along the main conveyor belt. Two sensorsare placed at each end of the main conveyor beltwith the other two sensors placed in-between. The location of each sensoralong the main conveyor beltis recorded in the control systemsuch that as the lumber L passes by each sensor, the sensor sends a signal to the control systemand the control systemknows where the lumber is positioned along the branch conveyor system.

The branch conveyor systemalso includes at least one end stoplocated at the back endof the branch conveyor system. The end stopprevents the lumber L from falling off the branch conveyor systemwhen the lumber reaches the end of the main conveyor beltand secondary conveyors. In the preferred embodiment, an end stopis located at the end of the main conveyor beltand each secondary conveying element. As the lumber L contacts the end stop, the movement of the lumber is stopped while the main and secondary conveyor belts,are allowed to continue to move, sliding underneath the lumber. In this manner, the branch conveyor systemis able to continue to transport additional pieces of lumber L received from the trunk conveyor systemto the back endof the branch conveyor system. As multiple pieces of lumber L are transported by the branch conveyor system, they will gather and form a backup at the back endof branch conveyor system if they are not removed. In this case, the branch conveyor system sensorscan sense this backup and tell the control systemhow full the branch conveyor systemis. When the backup reaches the sensorlocated near the front endof the branch conveyor system, a signal can be sent by that sensor to the control system, indicating to the control system not to direct any more pieces of lumber L to the branch conveyor system. A backup is detected by a branch conveyor system sensorwhen the sensor continues to sense the lumber L in front the sensor even though the main conveyor beltcontinues to move. The lumber L continues to be sensed by the sensorbecause the lumber does not move past the sensor.

The branch conveyor systemis particularly configured to hold truss members of different lengths and sizes without the truss members racking and falling off the branch conveyor system. Shorter length truss members will be entirely supported by the main conveyor belt, which is relatively wide so that the main conveyor belt can support the entire length of shorter truss members. However, longer truss members are supported by the main conveyor beltand secondary conveying elements. The belt of the main conveyor beltis constructed to provide a force to drive the truss members to the end stop. Once the leading truss member hits the end stop, its forward movement is halted and the main conveyor beltslides underneath it. The second truss member hits the leading truss member and also stops with the main conveyor beltsliding underneath it, and so on. The secondary conveying elementsare preferably formed by outboard roller chains. These chains carry rollers that engage and provide driving force to advance the longer truss members toward the end stop. However, when the longer truss members engage an obstruction (e.g., by engaging the truss member in front of it or the stop), the rollers will roll and pass under the longer truss members so that they impart no more than a negligible force on the longer truss members. As a result, the secondary conveying elementsdo not cause the longer truss members to become skewed (or to “rack”) when truss members back up on the branch conveyor system.

Referring to, a truss tableis positioned adjacent to the back endof the branch conveyor system. The truss tablegenerally includes a large, flat support surface with a jigging system allowing an operator to quickly position the lumber L to form a truss. Each truss tableis made up of a plurality of truss table sections(). The number of truss table sectionsin each truss tablecan vary depending upon the desired length of the truss table (e.g., the more truss table sections, the longer the truss table). Further details of truss tables may be found in U.S. Pat. Nos. 6,702,269 and 6,807,903, incorporated herein by reference. The operator grabs the lumber L delivered to the back endof the branch conveyor systemand arranges the lumber on the truss tableto form the truss. Because the pieces of lumber L are delivered next to the truss table, the operator is able to quickly grab the pieces of lumber L from the branch conveyor systemand position them on the truss table. This significantly reduces the time and energy the operator must spend in transporting the pieces of lumber L to the truss table. Alternatively, one or more robotic cells, as discussed below, may be configured to pick up the pieces of lumber L from the branch conveyor systemand arrange the pieces on the truss table. In a preferred embodiment, the truss tablemay have its own truss table software that interacts with the control system. For example, the truss tablemay be informed of the particular truss to be assembled on it and automatically position locating stopson the table in proper position. However, even before action is taken on the truss table, truss table software may determine the ideal orientation of the truss to be assembled on the truss table, taking into account the size of the truss, the location of completed truss ejectors on the table, etc. Once the optimized orientation is determined, this may be shown on a viewing screen near the truss tableto assist the assemblers (e.g., operators) in placement of the truss members. In some embodiments, the truss members carry printed information about where they are to be placed in on the truss tableto form the truss, and where nailing plates to interconnect the truss members are to be located. It is also possible to use an overhead laser projection system to put the image of the truss on the truss table, as directed by the truss table software, and provide information where truss members and nailing plates are to be located.

Referring to, another receiving unit that can be positioned adjacent to and receive lumber L from the trunk conveyor systemis a waste collection system. In the illustrated embodiment, the waste collection systemis a bin or container positioned to collect the pieces of lumber L as they fall off the trunk conveyor system. The bin can be placed adjacent to the rear endof the trunk conveyor systemand receive the pieces of lumber L as they fall off the end of the first conveyor belt. The bin can also be placed adjacent the first or second side of the first conveyor beltand receive the pieces of lumber L as they are pushed by the swing arm. In the preferred embodiment, the lumber L the bin collects is the waste from the cutting system. However, configurations where the bin collects remainders or truss members is also contemplated.

Referring to, another receiving unit that can be positioned adjacent to and receive lumber L from the trunk conveyor systemis a ramp assembly. The ramp assemblyincludes a main rampwith an angled surfacewith a top edgeand a bottom edge. The top edge is placed next to the first conveyor belt. The angled surfacecan be a flat piece of material or it can be formed from a plurality of rollers, as illustrated, in a parallel configuration with each other and the top and bottom edges,of the angled surface. A configuration where the plurality of rollers are parallel with each other but not with the top and bottom edges,of the angled surfaceis also contemplated. A restis located near or at the bottom edgeand extends above the angled surfaceto prevent the pieces of lumber L from sliding off the main ramp. In the preferred embodiment, the ramp assemblyis positioned next to the first or second side of the first conveyor belt. In this arrangement, the top edgeof the main rampis adjacent to and generally parallel with the first or second side of the first conveyor belt. The swing armcan then push the lumber L from the first conveyor beltonto the ramp assembly. Once the lumber L is on the ramp assembly, the lumber slides down the angled surfaceand stops against the restor other pieces of lumber already on the main rampof the ramp assembly.

As shown in, the ramp assemblymay include the main rampand one or more secondary ramps. The secondary rampsare generally the same as the main rampexcept that the secondary ramps have a smaller width. In other embodiments, the secondary ramps may have the same width as the main ramp. The main and secondary ramps,are generally parallel with each other, with the top edgeof each ramp positioned by one of the sides of the first conveyor belt. The inclusion of the secondary rampsallows the ramp assemblyto support longer pieces of lumber L than could be supported by just the main ramp.

Referring to, the lumber cutting and delivery systemmay include one or more robotic cellspositioned next to one or more of the components of the lumber cutting and delivery system. For example, as shown in, a robotic cellcan be positioned by the ramp assembly. The robotic cellmay also be positioned next to the back endof the branch conveyor system. The robotic cell includes a rotating base, a first armconnected to the base, a second armconnected to the first arm and a head. The base, first arm, second armand headare all movable relative to one another. In one embodiment, the baseof the robotic cellis movably mounted on a track (not shown), such as a set of rails, to permit the robotic cell to move between two or more locations along the track. The headcan pick up a piece of lumber L using suction or other gripping methods known in the art. The robotic cellis configured to pick up a piece of lumber L from one location, such as a receiving unit, and move the piece of lumber to another location. For example, a robotic cellcan move one or more pieces of lumber L from a ramp assemblyto an automated guide cart (not shown), a manual cart (not shown), or pallet (not shown). It is understood the robotic cellcan be used with other components of the lumber cutting and delivery systemas well. For example, a robotic cellmay be used to load a bunkwith lumber L. In one embodiment, one or more robotic cellscan be positioned adjacent to the back endof the branch conveyor systemso that the robotic cell can pick up the pieces of lumber L from the branch conveyor system and arrange the pieces on the truss tableto assemble the wooden truss. It is understood that the robotic cellmay be used to move pieces of lumber L between other components of the lumber cutting and delivery systemthan described herein. Each robotic cellcan be in communication with and/or operated by the control system.

The lumber cutting and delivery systemmay also include one or more automated guide carts (not shown). The automated guide carts are configured to transport one or more pieces of lumber L to different components of the lumber cutting and delivery system. The automated guide cart may include a storage area where pieces of lumber L can be stacked. Once the storage area of the automated guide cart is loaded with pieces of lumber L, the automated guide cart can move the pieces of lumber to another location. For example, after the robotic cellhas loaded the automated guide cart with lumber L, the automated guide cart can transport the lumber to a truss table, back to the loading system, to a lumber disposal area or to a component that is not part of the lumber cutting and delivery systemsuch as a standalone truss table. Alternatively, the automated guide carts may not include a storage area but instead pull a separate cart that is configured to hold the pieces of lumber L. Automated guide carts are generally known in the art and, thus, a detailed description is omitted here. Generally, each automated guide cart includes a driver configured to move the cart and a controller configured to operate the driver to move the automated guide cart to the various designated locations. The automated guide cart may also include scanners and/or sensors configured to sense the surrounding area and/or the payload (e.g., lumber L) being carried by the cart. Each automated guide cart is in communication with (e.g., wireless communication) and/or operated by the control system.

Another receiving unit that can be positioned adjacent to and receive lumber L from the trunk conveyor systemis the stacker (not shown). The stacker can be positioned between the trunk conveyor systemand the branch conveyor system. The stacker receives the lumber L from the trunk conveyor systemin a similar manner to how the branch conveyor systemreceives the lumber from the trunk conveyor system. The swing armof the trunk conveyor systempushes the lumber L onto the stacker. The stacker then moves the piece of lumber L into a stacked configuration with other pieces of lumber. The stacker is connected to and controlled by the control system. Upon receiving a signal from the control system, the stacker moves the lumber L from the stacked configuration onto the branch conveyor system. Using the stacker allows the lumber L to be moved off the trunk conveyor systemand stored in the stacker until the lumber is ready to be delivered to the truss tableby the branch conveyor system. The stacker can also be used without the branch conveyor system, collecting and storing the lumber L received from the trunk conveyor systemuntil an operator unloads the lumber.

Additional trunk conveyor systemsand transition conveyors, as described above, can also be receiving units, as described below.

Having described the different components of the lumber cutting and delivery systemof the present invention, namely the loading system, the infeed conveyor, the cutting system(e.g., saw), the transition conveyor, the trunk conveyor system, the branch conveyor system, the truss table, the stacker, the ramp assembly, the robotic cell, the culling station and the automated guide cart, the modular nature of the system will now be described. The modularity of the system allows the lumber cutting and delivery systemto be arranged in numerous different configurations to meet the truss building needs of different operators.

Each component of the lumber cutting and delivery systemcan be arranged in different combinations with the other components. Generally speaking, the lumber cutting and delivery systemwill typically have the loading system, the infeed conveyorand cutting systemat the beginning (e.g., beginning of a line) to select and cut the lumber L to the required shape and length. For example, the control systemmay receive information from truss design software, and thus, knows the various truss members needed for each truss, as well as the total number of trusses to be made in a particular work period. From there any number of trunk conveyor systemsand/or transition conveyorscan be arranged to transport the processed lumber L from the cutting systemto any number of different receiving units. Moreover, as shown in, in one embodiment, the lumber cutting and delivery system′ can include multiple lines(e.g., assembly lines), by having multiple loading systems, infeed conveyorsand cutting systemsalong with the corresponding conveyor systems and truss tablesto increase the overall production capacity of the system. Lumber cutting and delivery system′ is the generally the same as lumber cutting and delivery systemexcept that lumber cutting and delivery system′ includes four lines(e.g., assembly lines) whereas lumber cutting and delivery systemonly has one line.

The lumber cutting and delivery systemcan be arranged to deliver cut truss members to one or more (e.g., two, three, four, etc.) truss tables. For example, in the embodiment illustrated in, the lumber cutting and delivery systemtransforms a standard piece of dimensioned lumber L into a truss member and delivers that truss member to a single truss table. However, if a second truss tableis desired in order to build two trusses at once, the systemcan be arranged to support two truss tables(see). An additional branch conveyor systemcan be added so that the trunk conveyor systemhas one branch conveyor system on the first side of the first conveyor beltthat delivers lumber L to a first truss tableand another branch conveyor system on the second side of the first conveyor belt that delivers lumber to a second truss table. After the trunk conveyor systemreceives the pieces of lumber L from the cutting system, the ejectordirects the piece of lumber to the correct branch conveyor systemso that the piece of lumber is delivered to the truss tablerequiring that particular piece of lumber. This direction or sorting system will be discussed in more detail below. The waste collection systemcan be added to the rear endof the trunk conveyor systemto collect any pieces of lumber L not directed to one of the branch conveyor systems(see).

Additional trunk conveyor systemscan also be arranged in the lumber cutting and delivery system(see). The front endof each additional trunk conveyor systemcan be positioned adjacent to and in line with the rear endof the previous trunk conveyor system. In this manner, the trunk conveyor systemsare positioned in end to end relation with respect to one another such that the lumber L travels from one trunk conveyor system to the next trunk conveyor system. Likewise, if a greater distance is required between trunk conveyor systems, additional transition conveyorscan be placed in between trunk conveyor systems in a similar end to end manner to transport the lumber L the desired distance (see). Thus, it is apparent that for each additional trunk conveyor systemadded to the lumber cutting and delivery system, additional pathways or options are available to direct the lumber L to more locations and other lumber receiving units.

For example, if construction of a large truss requiring one large truss tableas shown in(or two truss tables) is desired, the lumber cutting and delivery systemhaving two trunk conveyor systemscan be used. Each trunk conveyor systemhas a branch conveyor systempositioned adjacent to the first side of a corresponding one of the first conveyor beltsto deliver the lumber L to the truss table. For example, the truss members for one end of the large truss can be directed to the first in line branch conveyor systemand the truss members for the other end of the large truss can be directed to the second in line branch conveyor system. If the distance between the two truss tablesis great enough, a transition conveyormay be placed between the two trunk conveyor systems(see). As the first in line trunk conveyor systemreceives the lumber L from the cutting system, the ejectorcan push the lumber required for the part of the truss being constructed on one end of the truss tableonto the corresponding branch conveyor systemwhile allowing the other pieces of lumber required to construct the part of the truss being construction on the opposite end of the truss table to be transported to the second in line trunk conveyor system. Alternatively, a ramp assemblyor other receiving unit described herein can be positioned on the second side of the first conveyor beltof the first in line trunk conveyor system. The ejectorof the first in line trunk conveyor systemcan then direct the lumber L, such as remainders, onto the ramp assemblyor other receiving unit. As the second in line trunk conveyor systemreceives the lumber L from the first in line trunk conveyor system, the ejectorcan push the lumber required to construct the part of the truss being constructed on the opposite end of the truss tableonto the branch conveyor system. In this manner, the lumber cutting and delivery systemcan deliver truss members to the section of the truss table(in this case the either end) the truss member will be positioned on to form the truss. In this example, a waste collect systemcan be located at the rear endof the second in line trunk conveyor systemto receive any lumber L not moved off the conveyor line by an ejector. Additionally, another receiving unit can be positioned along the second side of the second in line trunk conveyor system. This receiving unit can be another branch conveyor systemto transport pieces of lumber L to another truss table.

Thus, it is apparent that by adding additional trunk conveyor systemsa multitude of arrangements fitting the needs of the truss production facility can be created. The ability of each trunk conveyor systemto transport the lumber L to three different receiving units allows the system to be expanded or altered as desired. The modularity to select from a variety of receiving units grants the flexibility to create a lumber cutting and delivery systemcustomized to fit the truss building needs. Moreover, the ability to add additional lines(e.g., assembly lines) to the lumber cutting and delivery systemallows an increase in the overall production capacity of the system.

Having described the different components of the lumber cutting and delivery system, the control systemwill now be described. The control systemcontrols/operates/directs every controllable component of the lumber cutting and delivery system(e.g., cutting system, not passive components like the waste collection system or ramp assembly). Specifically, the control systemcontrols the operation of the loading system, infeed conveyor, cutting system, any transition conveyors, any trunk conveyor systems, any branch conveyor systems, culling station, any stackers, any automated guide carts, and any robotic cells. Broadly, the control systemincludes all the software (e.g., programming) configured to operate the lumber cutting and delivery systemand any controllers or computers (e.g., hardware) configured to execute the software on the various components of the lumber cutting and delivery system.

Referring to, an exemplary schematic illustration of the control systemis shown. The control systemincludes a central control stationthat has a display, a user interface and a computer connected to the user interface and the display (e.g., a desktop computer). The computer contains production software that is configured (e.g., programmed) to operate the lumber cutting and delivery system. One example of a suitable production software is MiTek Virtual Plant (MVP), although other production software is within the scope of the present invention. A production manager may access and interface with the production software via the display and user interface to set and control (e.g., manage) the operation of the lumber cutting and delivery system. The central control stationcan be located remote of the lumber cutting and delivery systemor next to a component of the lumber cutting and delivery system, such as the cutting system. For example, in one embodiment, the central control stationis located in an office adjacent the production floor containing the lumber cutting and delivery system. The central control stationis in wireless and/or wired communication with other components of the control system.

To operate the lumber cutting and delivery system, the production manager may, in one embodiment, import one or more truss design files containing data related to one or more truss designs into the production software via the central control station. The truss design files are created by truss design software. The production software is programed (broadly, configured) to allow the production manager to decide, for example, which truss designs are to be constructed by the lumber cutting and delivery systemand how many truss designs are to be constructed. The production software also includes data (e.g., size, physical relationship to other components, etc.) about all the truss tablesin the lumber cutting and delivery systemand is configured to select the appropriate truss table on which to assemble and arrange the truss members to construct the wooden truss or other wooden construct. In one embodiment, the production software is programmed to allow the production manager to select the truss tableon which to construct the wooden truss. The production software may also be programmed to show, via the display, a virtual layout of the lumber cutting and delivery systemand show information relating to the operation of the system to the production manager. Accordingly, the production software is programmed to receive data (e.g., performance data, history data, etc.) from the other components of the control system. This data can then be used by the production software to show the information relating to the operation of the lumber cutting and delivery systemand/or generate history and/or performance reports about the operation of the system.

The control systemincludes communication software in communication with the production software and configured to receive information from the production software and distribute that information to other components of the lumber cutting and delivery system. The communication software can be run on the central control stationor a separate device (e.g., computer, server) in communication with the central control station. In one embodiment, the communication software is integral (e.g., a part of) the production software and is not a separate software program. Upon receiving an appropriate input signal (e.g., start, begin) via the user interface of the central control stationfrom the production manager, the production software reads the truss design files and generates and sends one or more sets of job instructions (e.g., data) to the communication software based on the truss design files. Each set of job instructions corresponds to one truss design and contains all the necessary data (e.g., instructions, parameters, inputs) in order to operate the components of the lumber cutting and delivery systemto produce the truss design. Accordingly, each set of job instructions includes, but is not limited to, data about the various truss members that make up wooden truss (e.g., sizes, lengths, dimensions, cut angles, etc.), printing data for the printer to mark the truss members, arrangement data relating to the specific arrangement of the various truss members in the wooden truss, truss table identification data identifying the truss tablethe wooden truss is to be assembled on and, therefore, where the truss members need to be transported to, etc. The communication software is configured to then send at least a portion of the job instructions to the various appropriate components of the lumber cutting and delivery systemso the instructions can be executed. The communication software may also generate and send new instructions to the various components based on the received job instructions.

In one embodiment, the communication software may include a scheduling software module configured to schedule the order the job instructions are sent out and, thus, the construction order of the wooden trusses, and more specifically the truss members, by the lumber cutting and delivery system. The scheduling software module may schedule the jobs in a first-in/first-out manner or a priority-based manner based on information put into the production software (e.g., the production manager indicates certain wooden trusses are to be constructed before others). Other ways of scheduling the jobs are within the scope of the present invention.

The communication software may also include an optimization software module configured to optimize the creation of the wooden trusses or constructs. The optimization software module is configured to analyze each set of job instructions and optimize a parameter which can be chosen by the production manager via the production software. For example, and without limitation, the parameter may be to minimize waste generated by the cutting system, or minimize the cost of operating the cutting system, or minimize the number of cuts performed by the cutting system. The optimization software module schedules the cutting of lumber L by the cutting systemto optimize the chosen parameter. For example, to minimize waste, the optimization software module schedules the cutting of lumber L to maximize the number of truss members cut from each piece of lumber (e.g., maximize the amount of each piece of lumber used to create truss members). This may include cutting multiple truss members from a single piece of lumber L or cutting the piece of lumber to create a remainder, not waste. To minimize the number of cuts performed by the cutting system, the software module schedules the cutting of lumber L so that truss members which share a corresponding cut angle are cut from the same piece of lumber L, thereby allowing the cutting systemto make one cut for two truss members. The optimization software module can optimize the parameter on an individual truss basis (e.g., while cutting the truss members for a single truss) or on a multi-truss basis (e.g., while cutting the truss members for multiple trusses). The optimization software module may also optimize the positioning of the truss members on the truss table(e.g., arrangement and orientation of the wooden truss on the truss table) so that the maximum number of connector plates are supported by the truss table (e.g., minimize the number of connector plates positioned over the slots in the truss table the stops move in). Optimizing the position of the truss members on the truss tablemay also be done by the truss table software, as described herein.